Heat exchange apparatus



June 18, 1940. L LARRECQ HEAT EXGRANGE APPARATUS 3 Sheets-Sheet 1 FiledJuly 27, 1937 Inventor Anthong J.L.arr-ec Hi Attorr" 65-1.;

June 18, 1940. A. J. LARRECQ mm EXCHANGE APPARATUS Fil d July 27, 1937 sSheets-Sheet 2 Inventor: Anthony J. Larrecq, 9

His Attorney June 18, 1940. J. RREQ 2,205,266

HEAT EXCHANGE APPARATUS Filed July 27, 1957 3 Sheets$heet 3 Inventor:Anthong J Larrecq,

His Attorney.

Patented June 18, 1940 PATENT OFFICE HEAT EXCHANGE APPARATUS Anthony- J.Larrecq, Beach Bluff, Mass., assignor to General Electric Company, acorporation of New York Application July 2'1, 1937, Serial No. 155,935

21 Claims. 7 (01. 105-35) The present invention relates to heat exchangeapparatus for use with motor vehicles. Al-

directly or indirectly by means of an elastic op-.

erating fluid such as steam which is desired to be continuouslyrecondensed and reutilized.

It is an object of the invention to provide an air-cooled heat exchangeapparatus capable of condensing the. exhaust fluid of a locomotiveengine with very little loss of such fluid, thereby to reduce to a smallvalue the amount of makeup fluid necessarily supplied during a given runof the locomotive.

A further object is to provide in connection with a locomotive structurean arrangement of condenser apparatus which is adapted to conserve spacebut which nevertheless permits free accessv to operative parts of theapparatus and free passage through the compartment which contains theapparatus to other sections of the locomotive.

A further object is to provide a surface-type condenser which willoperate eificiently under the conditions encountered in a locomotive orother motor vehicle.

A further object is to provide in connection with a motor vehicle a heatexchanger which is so constructed and mounted as to withstand thevibrational and other stresses encountered during the operation of thevehicle.

In the preferred embodiment of the invention as applied to a locomotive,heat exchangers constituting condensers are arranged adjacent the outerwalls of a compartment of the locomotive in such a way as to permit airdrawn through such walls to be forced across the heat exchange surfacesof the condensers. The air is expelled through the roof of thecompartment by means of a blower appropriately arranged, and condensateis collected in a reservoir in the compartment floor. All the elementsreferred to are so arranged as to provide a free passageway through thecompartment in a direction lengthwise of the locomotive.

In orderto obtain eflicient operation of the heat exchangers, each heatexchanger comprises "a main condenser section and an after-coolersection, these being preferably so located that the cooling air passesfirst over the after-cooler section and then over the condenser section.As a result, gases drawn from the heat exchanger at the after-cooler endconsist largely of noncondensables and contain very little operatingfluid. Correspondingly little fluid has therefore to be supplied, to thesystem for make-up purposes. I To impart a reasonable degree offlexibility to the heat exchangers, they are preferably mainly supportedfrom thetop of the locomotive structure and are more or less flexiblysecured at their lower ends in a manner which will be more fullydescribed hereinafter.

The features of novelty which I desire to protect herein will be bepointed out with particularity in the appended claims. The inventionitself, together with further objects and advantages thereof, will bestbe understood by reference to the following description taken inconnection with the drawings in which Fig. 1 is a diagrammatic view of acomplete locomotive exemplifying one application of the invention; Fig.2 is a diagrammatic plan view showing a preferred arrangement ofcondensing apparatus with respect to otherparts of a locomotivestructure; Fig. 3 is a sectional view taken on line 3-3 of Fig. l andshows further aspects of the condensing apparatus arrangement; Fig. 4 isa fragmentary detail view in section of one element shown in Fig. 3;Fig. 5 is a view in perspective of a preferred .form of heat exchangerconstructed in accordance with the invention; Figs. 6 and 7 arefragmentary details of particular elements appearing in Fig. 5, and Fig.8 is a plan view similar to Fig. 2 but illustrating analternative modeof applying the invention.

Since it is particularly adapted for such use, the invention will bedescribed as applied to a turbo-electric locomotive, that is, alocomotive which employs an elastic fluid turbine as a prime mover andan electric generator and motor combination for transmitting the energydeveloped by the prime mover to the driving wheels of the locomotive. Bycondensing the exhaust fluids of the turbine a low back pressure may bemaintained and high turbine efliciency realized.

Furthermore, the rate at which make-up fluid must be supplied may bereduced to a low value so that long continuous runs without rewateringbecome possible, this being a factor of considerable importance inmaintaining high speed locomotive schedules.- v

The locomotive which is illustrated in Fig. 1 is of reversible type andcomprises a pair of similar units arranged at the opposite ends of thelocomotive structure. As will be seen more clearly in Fig. 2, each halfof the train includes a control compartment, 'a power plant compartment,and a condensing compartment interposed between the other two. Thesecompartments correspond to the sections of the locomotive designated bythe numerals l 0, I2, and II respectively and may or may not be actuallyseparated from one another by means of bulk-heads.

In the particular construction illustrated the p'ower plant compartmentincludes a boiler I5, preferably heated by a'liquid fuel burner (notshown), an elastic fluid turbine comprising a high pressure section l8and a low pressure section "and an electric generator Ill connected t0the turbines by a gearing l9 or in any suitable manner. The powerdeveloped by the generator is transmitted to electric motors (not shown)which are mechanically connected to the driving wheels of the locomotiveand controlled by suitable equipment in the control compartment.

The elastic operating fluid flows from the boiler l5 through a conduit20 and then serially through the turbines l6 and IT. From the exhaust ofthe latter it is led by means of a conduit 2| to a pair of surfacecondensers 22 and 23 disposed at opposite sides of the condensingcompartment. The condensate is received in a liquid reservoir or hotwell 24 from which it is returned to the boiler by means of a pump 25and aconduit 26 (see Fig. 1).

It is desirable that the various parts of the locomotive be accessiblefrom either ofthe con trol compartments. Accordingly, the arrangement ofthe power plant and condensing apparatus is preferably such that a freepassageway is provided throughout the entire length of the locomotive.This may be accomplished as far as the power plant compartment isconcerned, by positioning the boiler l5 and the turbines and generatorin spaced'relation on opposite sides of a passageway, such as isindicated at 28.

In Fig. 3 I have illustrated an arrangement whereby the passageway 28may be extended through the condensing compartment while at the sametime realizing-a compact and efiective disposition of the condensingapparatus. In the arrangement shown surface type heat exchangerscorresponding to the condensers 22 and 23 of Fig. 2 are arranged alongthe outer walls of the condenser compartment. Condensate formed in theheat exchangers is received and retained in a hot well or reservoir 30in the floor of the compartment. Air inlets are provided in the wallsadjacent to the heat exchangers and an air outlet comprising a grille 3|is formed in the roof of the compartment.

In order to force air through the compartment with the desired velocityI may utilize one or more blowers arranged adjacent to the air outlet.If a single blower is used as shown, it must necessarily be ofrelatively large size and of heavy construction, and it is thereforenecessary that a substantial supporting means be provided for it. Inaccordance with the invention such means is provided in the form of aliquid storage chamber or tank 33 which may be used for liquid fuel-for,the power plant burners or for a reserve supply of make-up waterfor the boiler. In the arrangement indicated in Fig. 2, it is used forthe former purpose and connected with the burner by means of a conduit34 (Fig. 2).

The tank is preferably formed to define an arch 35 disposed transverselyof the compartment and may be sufficiently strong to support the blowerand suitable apparatus for driving the same. (Such apparatus maycomprise, for example, an exhaust turbine 37, as shown, or a worm geardrive connectingwith a motive elementwhich is disposed at some pointrelatively remote from the blower.) The tank is given an upwardlytapered shape and in combination with-deflecting vanes 38 and guidewalls 39 (see Fig. 2) is efiective to direct the air stream upwardlytoward the roof outlet. A special advantage of this arrangement asapplied to a fuel storage tank is that the heated air proceeding fromthe condenser surfaces maintains the tank and the enclosed liquid fuelata rel atively high temperature effective to facilitate combustion in thepower plant burners.

The particular form of blower illustrated comprises a set of stationaryvanes 40 arranged adjacent to the outlet grille and a set of fan bladesor rotary vanes 4| (see Fig. 3). In order accurately to adjust theclearances of the rotating blades-with respect to the walls of the airpassage, an adjustable stationary ring or sleeve 43 is providedsurrounding the blades. This sleeve is secured to and supported by anenclosing cylinder 44 by means of screws 45 which may be tightened orloosened to vary the position of the sleeve with respect to the fanblades. Preferably, the screws 45 also constitute shear pins which maybe severed in case excessive vibrations or distortion of thelocomotive-frame brings the (1 fan blades into contact with the sleeve43.

Referring now specifically to the condensing apparatus, an importantaspect of my invention consists in constructing the heat exchangers insuch a way that each exchanger comprises a condenser section and anafter-cooler section.

- Referring particularly to Fig. 5, which shows the details of one heatexchanger, it will be seen that the upper part of the exchangercomprises a header structure illustrated as a fabricated boxlikestructure 53 having a cover plate 54 boltedthereto in an air-tightmanner. The cover plate is provided with a series of transverse ribs 56adapted to give it greater rigidity with respect to pressure differencesbetween the inside and the outside of the header structure. Thestructure 53 itself comprises a plurality of longitudinally extendingchambers including a pair of chambers 58 and 59 arranged relativelyremote from the outer sidewall of the locomotive and another pair ofchambers GI and 62 disposed adjacent to such wall. The relative locationof these chambers is such that the mixed elastic fluid andnon-condensables entering through the conduit 2| pass first into theheader chamber 58 and then downwardly through a group of condenser pipes64 which connect with that chamber. These pipes are preferably providedexternally with fins of either helical or continuous fin type in orderto increase their heat dissipating capacity. At the bottom of the heatexchanger there is provided a lower header structure 65 also connectingwith the heat exchange tubes and affording cross-over connectionsbetween the tubes more remote from the compartment wall and thoseadjacent to the wall. By means of this connection vapors which pass in adownward direction through tubes 64 are able to pass upwardly throughthe outer row of tubes 66 into the header 62. A large proportion of thesteam or other elastic fluid contained in the exhaust from the turbineis condensed during downwardfiow through the tubes 64, so that the tubes66 receive primarily non-condensables. To increase the velocity of flowthrough the after-cooler section thus formed the total crosssectionalarea of the tubes 66 may be made a small fraction, say 15%, of the totalcross-sectional area of the condensing tubes 64.

In order to prevent air binding and consequent imperfect operation ofthe heat exchanger, I prefer to provide for continuously extracting theair and other non-condensables. Because in the preferred operation ofthe heat exchanger its internal pressure is below atmospheric pressure,some positive pumping means must be provided to make such extractionpossible. As previously indicated, the after-cooler tubes 66 arearranged to contact the cooling air before it reaches the condensertubes and while it is at its lowest temperature. For this reason, thevolcomprising a conventional steam ejector I connecting through aconduit 'II with the aftercooler header 62. Live steam is fed into theejector I0 through a pipe I3 and is discharged with entrainednon-condensables into the header section 59. From this header theadmixed steam and non-condensables are passed through an auxiliarycondenser comprising finned tubes I connecting with the header section59. By means of a cross-over connection provided in the lower header 65and indicated at 6B in Fig. 5, these gases may also be passed through anaftercooler tube I6 to promote the further condensation of the steam andits separation from the non-condensables. From the after-cooler tube ISthe non-condensables pass to the header 6| whence they are exhausted toatmosphere by means of an exhaust connection I8.

Under certain conditions it may be desirable to improve thecharacteristics of the condenser by spraying at least the after-coolertubes with an evaporative fluid such as water. Means for accomplishingthis result are illustrated as comprising a series of spray tubes BI(Fig. 5). While these tubes are shown in the drawings as being partlycut away, it will be understood that in use they actually extendsubstantially the entire length of the heat exchanger. A detail view ofone such tube is shown in Fig. 7 in which it appears that the tube isprovided with outlet orifices 82 to permit a stream of water to beejected therethrough.

Expansion considerations and the types of vibration normally encounteredin high speed 1000- ent invention this is accomplished by connect ingtheupper header structure substantially rigidly to the vehicle body andresiliently anchoring the lower header. Referring to Fig. 3 it will beseen that structural members 85 define at opposite sides of thelocomotive a pair of longitudinally extending chambers at'the top of thecondenser compartment. Each ofthe upper header structures for the heatexchangers is disposed within one of these chambers and secured to thestructural members in a manner indicated more fully in Fig. 5. Referringto that figure, it will be seen that the right-hand end of the upperheader structure is secured to a structural member 85 by means of a bolt86. At the other end of the header structure an expansionpermittingconnection is made by means of a curved expansion plate 88 having slotand pin connections with the structural members 05.

The lower header 65 at its right-hand end is resiliently anchored bymeans of a pin connection such as is illustrated in detail in Fig. 6.Such a connection may comprise, for example, a pin 9i connecting theheader 55 to a structural member 92 by means of a resilient bushing 93which may consist, for example, of rubber. At its other end the header65 is resiliently anchored by means of rubber buffers 85 interposed bymeans of conduits I23.

between the header and the framework of the vehicle body.

As previously explained a reservoir for condensate from the heatexchanger is provided at the bottom of the condenser compartment. Thismay include a channel I00 running longitudinally of the locomotive anddefinedin part by means of structural members 02 which form the vehiclebody framework. In order flexibly to connect the header 65 andcross-over 68 to the reservoir a connection such as is illustrated indetail in Figs. 3 and 4 may be used. This connection comprises aflexible metal bellows I05 tightly joined at its upper end to a wall I06of the reservoir chamber and at its lower end to a pipe I0'I connectingwith the header 65. The connection between the bellows I05 and the pipeI01 may be made, for example, by means of a gasketed joint I09 such asthat illustrated in Fig. 4. r

The efiectiveness of operation of the condenser system will obviouslyvary in dependence on the temperature of the cooling air. To compensatefor such variations it is possible to change the amount of cooling airdrawn into contact with the exchange tubes in accordance with changes inthe ambient temperature. This may be accomplished most efiectively bymeans tion that the condensing apparatus may com prise a plurality ofsections. Such an arrangement, comprising two sections, is illustratedin Fig. 8 where successively arranged heat exchangers I20 and I2I areshown as being interconnected With this arrangement each set of heatexchangers may be arranged in its own condensing compartment andprovided with a separate blower as indicated. With this arrangementvariations in the ambient temperature may be compensated by closingpartially or wholly the louvers pertaining to one compartment whileleaving the other louvers open. It may be noted as an additional resultof closing the louvers of a given compartment that the blower in thatcompartment is automatically substantially unloaded and its requireddriving power correspondingly reduced. This is a particular advantage incase the various blowers are driven by a common means, such as a lineshaft, so that they may not be independently shut down.

While I have described my invention particularly in relation to a steamlocomotive, it is equally applicable to other vehicles such as ships andaeroplanes, and in certain of its aspects to stationary condenserinstallations. Also, while I have illustrated a particular embodiment ofthe invention, it will be understood that many modiflcations may be madeby those skilled in the art without departing from the invention. Itherefore aim in the appended claims to cover all such alternativemodifications as come within the true spirit and scope of the foregoingdisclosure.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is: g

1. A motor vehicle comprising a first compartment containing an elasticfluid engine, a second compartment for the operation and control of thevehicle, and a third compartment interposed between the first and secondcompartments and containing means for condensing the elastic fluid, suchmeans comprising heat exchangers disposed along opposite walls of thecompartment, inlets for air in such walls, an outlet for air in the roofof the compartment, a blower arranged adjacent to the outlet for forcingair through the compartment, and a reservoir for condensate in the floorof the compartment, there being a free passageway through the thirdcompartment between the first and second compartments.

2. A motor vehicle comprising a first compartment containing an elasticfluid engine, a second compartment adjacent said first compartmentcontaining means for condensing the exhaust from said engine, such meanscomprising heat exchangers disposed along opposite side walls of thecompartment, an outlet for air in the roof of the compartment, a blowerarranged adjacent to the outlet for forcing air through the compartmentthere being a substantially enclosed passageway for vehicle operatorsthrough said condenser compartment and communicating with said enginecompartment.

3. A motor vehicle comprising a first compartment containing an elasticfluid engine, a second compartment for the operation and control of thevehicle, and a third compartment interposed between the first and secondcompartments and containing means for condensing elastic fluid, suchmeans comprising a pair of heat exchangers respectively disposed alongopposite outer walls of the compartment, inlets for air in such walls,an outlet for air in the roof of the compartment. a blower arrangedadjacent to the outlet for forcing air through the compartment, andmeans supporting the blower from the floor of the compartment, thesupporting means including a liquid storage chamber defining an archdisposed transversely of the compartment and providing a passagewaythrough the third compartment between the first and second compartments.

4. In a motor vehicle having an elastic fluid engine, means forcondensing the elastic fluid discharged from the engine, such meanscomprising a condensing compartment, air-cooled surface condensersdisposed along opposite walls of the compartment for receiving elasticfluid from the engine, inlets for air in such walls, an outlet for airin the roof of the compartment, a reservoir for condensate below saidcondensers, a blower arranged adjacent the. outlet for forcing airthrough the comm tment, and means supporting the blower, the suppbrtingmeans comprising a liquid storage chamber defining an arch disposedtransversely of the compartment and providing a passagewaylongitudinally of the compartment.

5. In a motor vehicle having a steam engine, and means including aliquid fuel burner for generating steam for the engine, a condensercompartment, air-cooled surface condensers disposed along opposite wallsof the compartment for receiving steam from the engine, inlets for airin such walls, an outlet for air in the roof of the compartment, ablower for forcing air through the compartment, and means including afuel storage chamber for the burner providing a passagewaylongitudinally of the compartment.

6. In a motor vehicle having a steam, engine, and means including aliquid fuel burner for generating steam for the engine, a condensingcompartment including a surface condenser for receiving exhaust steamfrom the engine, means for circulating cooling air through thecompartment and across the condenser, and a fuel storage tank connectingwith the burner and disposed within the condenser compartment, saidstorage tank being so arranged that air passing through the compartmentcomes first into contact with the condenser and then into contact withthe tank.

'I. In a motor vehicle, a condenser installation adapted to withstandvibrational stresses encountered during operation of the vehicle, saidcondenser installation including an upper header substantially rigidlysecured to the vehicle body, a lower header, heat exchange tubesconnecting the upper and lower headers, a reservoir adjacent to thelower header for receiving condensate therefrom, the reservoir beingsubstantially rigidly secured to the vehicle body, means resilientlyanchoring the lower header to the vehicle body, and means flexiblyconnecting the lower header to the reservoir.

8. In combination, a locomotive compartment, structural members defininga pair ,of longitudinally extending chambers adjacent to opposite sidesof the compartment and at the top of the compartment, surface typecondensers respectively'disposed along each of such sides, eachcondenser including an upper header structure disposed in one of thesaid chambers and secured to said structural members, heat exchangetubes communicating with and depending from the upper header structureand a lower header structure joining with the tubes, reservoirs at thebottom of the compartment for receiving condensate from the condenser,means flexibly anchoring the lower header structures and additionalmeans flexibly connecting them with the reservoirs, and means forforcing air through the compartment in heat-exchanging relation with thecondensers.

9. In a motor vehicle, a condenser having an upper header and a lowerheader, heat exchange tubes connecting said headers, means ofsubstantiallyri'gidly securing said upper header to the vehicle bodyincluding means for allowing relative expansion movements between saidupper header and said vehicle body, and means for resiliently supportingthe lower header in said vehicle body.

10. In a motor vehicle, a condenser having an upper header and a lowerheader, heat exchange tubes connecting said headers, means forsubstantially rigidly securing one of said headers to the vehicle bodyincluding means for allowing rel-. ative expansion movementstherebetween, and means for resiliently supporting the other header insaid vehicle body.

11. In a motor vehicle, a surface condenser in- I eluding an upperheader for receiving elastic fluid to be condensed, a lower header, aplurality of heat exchange tubes connecting said headers, a reservoirfor condensate formed by structural members of said motor vehicle, meansfor resiliently supporting the lower header upon said structuralmembers, and a resilient connection between said lower header and saidreservoir.

12. In a motor vehicle, a condenser compartment, air cooled surfacecondensers disposed along opposite side walls of said compartment, meansfor resiliently supporting said condensers upon the floor of saidcompartment, a condenser reservoir defined at least in part by the.structural members of said compartment flooring and flex ibleconnections extending from said condensers for draining condensatetherefrom into said reservoir.

13. A condenser installation including a pair of spaced surfacecondensers defining a chamber therebetween, each condenser comprising aplurality of heat exchange tubes, means including a fan or the like fordrawing air across the tubes and into the chamber and for expelling itfrom the chamber, means dividing said chamber longitudinally fordirecting the air from said condensers toward said fan, saiddividingmeans providing a substantially enclosed passageway foroperators through said chamber.

14. A condenser installation comprising a condensing compartment, a pairof surface condensers disposed along opposite sides of the compartment,each condenser comprising a plurality of spaced heat exchange tubes,inlets for air adjacent each of the condensers, an outlet for air at thetop of the compartment, means for drawing air into the compartmentthrough such inlets and across the heat exchange tubes, and meansproviding a passageway through said compartment for directing the airupwardly toward the compartment outlet.

15. A surface condenser installation including a unitary upper headerstructure and a unitary lower header structure, a plurality of heatexchange tubes connected between the header structures, certain of saidtubes forming a condenser for an elastic fluid to be condensed, meansincluding a steam ejector for withdrawing noncondensables from thecondenser, a second condenser comprising others of the tubes forreceiving admixed steam and non-condensables from the ejector, means forexhausting the non-condensables from the second condenser, and means forforcing a cooling fluid across all of the tubes.

16. A surface condenser installation including a unitary upper headerstructure and a unitary lower header structure, a plurality of heatexchange tubes connected between the header structures, certain of saidtubes comprising a main condenser for receiving an elastic fluid to becondensed and an after-cooler for the main condenser, means including asteam ejector for withdrawing non-condensables from the aftercooler, anauxiliary condenser comprising others of the tubes for receiving admixedsteam and non-condensables from the ejector, an aftercooler for theauxiliary condenser comprising the remaining tubes, means for exhaustingnon-condensables from such after-cooler, and means for forcing a coolingfluid first into contactv with the after-cooler tubes and then intocontact with the condenser tubes.

17. In a motor vehicle having anelastic fluid generator including a fuelburner and an elastic fluid engine, a condenser compartment having heatexchangers arranged along opposite side ,walls for condensing theelastic fluid exhaust from said engine, openings in the side walls ofsaid vehicle adjacent said heat exchangers for admitting cooling airthereto, an outlet in the roof of said compartment, blower meansarranged adjacent said outlet for drawing air through said up positelyarranged heat exchangers and for expelling it through said outlet, meansincluding a storage reservoir for burner fuel longitudinally dividingthe lower portion of said heat exchanger compartment for directing airupwardly from said heat exchangers toward said outlet.

18. In a motor vehicle having an elastic fluid engine, a condensercompartment, heat exchangers arranged along opposite sidewalls of saidcompartment for condensing the elastic fluid exhaust from said engine,openings in the side walls of said compartment adjacent said heatexchangers for admitting cooling air thereto, blower means arrangedbetween said heat exchangers and adjacent. the roof of said compartmentfor drawing cooling air across said heat exchangers, an outlet openingin the roof of said compartment adjacent said blower means, meanslongitudinally dividing said compartment between said heat exchangersfor directing the air flow from said heat exchangers toward said blower,said last mentioned means providing an enclosed passageway through saidcompartment for motor vehicle operators.

19. In a locomotive vehicle having an elastic fluid engine, a condensercompartment in said vehicle, an opening in said compartment in the sidewall of said vehicle, vehicle framework members adjacent the oppositesides of said opening, a unitary condenser arranged in ,said compartmentacross said opening for condensing the elastic fluid exhaust of saidengine, said condenser having longitudinal upper and lower headers and aplurality of heat exchanging tubes arranged between said headers, saidupper header being secured rigidly at one end to the adjacent vehicleframework member and secured at the other end to the adjacent vehicleframework member so as to allow for expansion movements of saidcondenser, and means resiliently securing said lower header to the floorof said compartment.

20. In a locomotive vehicle having an elastic fluid engine, a condensercompartment in said vehicle, an opening in said compartment in the sidewall of said vehicle, a unitary condenser arranged in said compartmentacross said opening for condensing the elastic fluid exhaust of saidengine, said condenser having longitudinal upper and lower headers and aplurality of heat exchanging tubes arranged between said headers, meanslongitudinally dividing said upper header so as to cooperate withcertain of said tubes to form a main condenser section, and other ofsaid tubes to form an after-cooler section between said opening and saidmain condenser section.

21. In a locomotive vehicle having an elastic fluid engine, a condensercompartment in said vehicle, an opening in said compartment in the sidewall of said vehicle, a unitary condenser arranged in said compartmentacross said opening for condensing the elastic fluid exhaust of saidengine, said condenser having longitudinal upper and lower headers and aplurality of heat exchanging tubes arranged between said headers, meanslongitudinally dividing said upper header so as to cooperate withcertain of said tubes to form a main condenser section and'other of saidtubes to form an after-cooler section between said opening and said maincondenser section, means transversely dividing a portion of said upperheader and corresponding means transversely dividing a portion of saidlower header to cooperate with the third group of said tubes to providean auxiliary condenser section and means for withdrawing fluid from saidafter-cooler section and discharging it into said auxiliary section.

ANTHONY J. LARRECQ.

